Feasibility of photoelectron sources for testing the energy scale stablity of the KATRIN beta-ray spectrometer

TL;DR

This study investigates the feasibility of using photoelectron sources generated by gamma-ray absorption in thin metallic convertors to test the energy scale stability of the KATRIN beta-ray spectrometer, focusing on monoenergetic electron production around 18.6 keV.

Contribution

The paper presents calculations and experimental measurements demonstrating the potential of gamma-ray induced photoelectron sources for spectrometer calibration.

Findings

Photoelectrons with ~1 eV natural width can be produced at ~18.6 keV.

Gamma-ray sources 241Am and 119mSn effectively generate photoelectrons in Co and Ti convertors.

Experimental measurements validate the feasibility of this approach.

Abstract

Photoabsorption of nuclear gamma-rays in thin metallic convertors was examined with the aim to produce monoenergetic photoelectrons of kinetic energy around 18.6 keV and natural width of about 1 eV. Calculations were carried out for commercial photon sources of 241Am (1.1 GBq) and 119mSn (0.5 GBq) irradiating Co and Ti convertors. Photoelectrons ejected by 241Am gamma- and X-rays from Co convertors of various thickness were measured with two electrostatic spectrometers.